Abstract: A process for preparing lactose-free skimmed, partially skimmed and whole milk is proposed in which: (1) the milk is pasteurized and skimmed; (2) the skimmed milk is hydrolyzed enzymatically by a lactase; (3) the hydrolyzed skimmed milk is microfiltrated to obtain an ultrafiltration retentate (RMF) and a microfiltration permeate (PMF); (4) the PMF is ultrafiltrated and an ultrafiltration retentate (RUF) and an ultrafiltration permeate (PUF) are obtained, 5) the PUF is nanofiltrated and a first nanofiltration retentate (RNF1) and a first nanofiltration permeate (PNF1) are obtained, 6) the PNF1 is nanofiltrated to obtain a second nanofiltration retentate (RNF2) and a second nanofiltration permeate (PNF2), and 7) final step: lactose-free milk is obtained by mixing one or more of the fractions deriving from one or more of the previous steps.

Abstract: Process for preparing lactose-free skimmed, partially skimmed and whole milk, comprising the following steps: 1) pasteurization and skimming, 2) enzymatic hydrolysis of the skimmed milk by lactase enzyme, 3) microfiltration of the hydrolysed skimmed milk and obtainment of a microfiltration retentate (RMF) and of a microfiltration permeate (PMF), 4) PMF ultrafiltration and obtainment of an ultrafiltration retentate (RUF) and of an ultrafiltration permeate (PUF), 5) first PUF nanofiltration and obtainment of the first nanofiltration retentate (RNF 1) and of a first nanofiltration permeate (PNF 1), 6) second PNF 1 nanofiltration and obtainment of a second nanofiltration retentate (RNF2) and of a second nanofiltration permeate (PNF2), and 7) final step: obtainment of lactose-free milk by mixing one or more of the fractions deriving from one or more of the previous steps, which is characterized in that: (I) the first nanofiltration of step 5) is carried out with membranes having a molecular weight cut-off ranging